fib_trie: Update insert and delete to make use of tp from find_node (d5d6487c) · Commits · 戴 / test

net/ipv4/fib_trie.c

+95 −142

Original line number	Diff line number	Diff line
		@@ -300,7 +300,7 @@ static inline void empty_child_dec(struct tnode *n)
		n->empty_children-- ? : n->full_children--;
		}

		static struct tnode *leaf_new(t_key key)
		static struct tnode leaf_new(t_key key, struct fib_alias fa)
		{
		struct tnode *l = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
		if (l) {
		@@ -310,12 +310,14 @@ static struct tnode *leaf_new(t_key key)
		* as the nodes are searched
		*/
		l->key = key;
		l->slen = 0;
		l->slen = fa->fa_slen;
		l->pos = 0;
		/* set bits to 0 indicating we are not a tnode */
		l->bits = 0;

		/* link leaf to fib alias */
		INIT_HLIST_HEAD(&l->leaf);
		hlist_add_head(&fa->fa_list, &l->leaf);
		}
		return l;
		}
		@@ -842,10 +844,8 @@ static void resize(struct trie t, struct tnode tn)
		}
		}

		static void leaf_pull_suffix(struct tnode *l)
		static void leaf_pull_suffix(struct tnode tp, struct tnode l)
		{
		struct tnode *tp = node_parent(l);

		while (tp && (tp->slen > tp->pos) && (tp->slen > l->slen)) {
		if (update_suffix(tp) > l->slen)
		break;
		@@ -853,10 +853,8 @@ static void leaf_pull_suffix(struct tnode *l)
		}
		}

		static void leaf_push_suffix(struct tnode *l)
		static void leaf_push_suffix(struct tnode tn, struct tnode l)
		{
		struct tnode *tn = node_parent(l);

		/* if this is a new leaf then tn will be NULL and we can sort
		* out parent suffix lengths as a part of trie_rebalance
		*/
		@@ -866,51 +864,6 @@ static void leaf_push_suffix(struct tnode *l)
		}
		}

		static void fib_remove_alias(struct tnode l, struct fib_alias old)
		{
		/* record the location of the previous list_info entry */
		struct hlist_node **pprev = old->fa_list.pprev;
		struct fib_alias fa = hlist_entry(pprev, typeof(fa), fa_list.next);

		/* remove the fib_alias from the list */
		hlist_del_rcu(&old->fa_list);

		/* only access fa if it is pointing at the last valid hlist_node */
		if (hlist_empty(&l->leaf) \|\| (*pprev))
		return;

		/* update the trie with the latest suffix length */
		l->slen = fa->fa_slen;
		leaf_pull_suffix(l);
		}

		static void fib_insert_alias(struct tnode l, struct fib_alias fa,
		struct fib_alias *new)
		{
		if (fa) {
		hlist_add_before_rcu(&new->fa_list, &fa->fa_list);
		} else {
		struct fib_alias *last;

		hlist_for_each_entry(last, &l->leaf, fa_list) {
		if (new->fa_slen < last->fa_slen)
		break;
		fa = last;
		}

		if (fa)
		hlist_add_behind_rcu(&new->fa_list, &fa->fa_list);
		else
		hlist_add_head_rcu(&new->fa_list, &l->leaf);
		}

		/* if we added to the tail node then we need to update slen */
		if (l->slen < new->fa_slen) {
		l->slen = new->fa_slen;
		leaf_push_suffix(l);
		}
		}

		/* rcu_read_lock needs to be hold by caller from readside */
		static struct tnode fib_find_node(struct trie t, struct tnode **tn, u32 key)
		{
		@@ -980,61 +933,28 @@ static void trie_rebalance(struct trie t, struct tnode tn)
		{
		struct tnode *tp;

		while ((tp = node_parent(tn)) != NULL) {
		while (tn) {
		tp = node_parent(tn);
		resize(t, tn);
		tn = tp;
		}

		/* Handle last (top) tnode */
		if (IS_TNODE(tn))
		resize(t, tn);
		}

		/* only used from updater-side */

		static struct tnode fib_insert_node(struct trie t, u32 key, int plen)
		static int fib_insert_node(struct trie t, struct tnode tp,
		struct fib_alias *new, t_key key)
		{
		struct tnode l, n, *tp = NULL;
		struct tnode n, l;

		n = rtnl_dereference(t->trie);

		/* If we point to NULL, stop. Either the tree is empty and we should
		* just put a new leaf in if, or we have reached an empty child slot,
		* and we should just put our new leaf in that.
		*
		* If we hit a node with a key that does't match then we should stop
		* and create a new tnode to replace that node and insert ourselves
		* and the other node into the new tnode.
		*/
		while (n) {
		unsigned long index = get_index(key, n);

		/* This bit of code is a bit tricky but it combines multiple
		* checks into a single check. The prefix consists of the
		* prefix plus zeros for the "bits" in the prefix. The index
		* is the difference between the key and this value. From
		* this we can actually derive several pieces of data.
		* if !(index >> bits)
		* we know the value is child index
		* else
		* we have a mismatch in skip bits and failed
		*/
		if (index >> n->bits)
		break;

		/* we have found a leaf. Prefixes have already been compared */
		if (IS_LEAF(n)) {
		/* Case 1: n is a leaf, and prefixes match*/
		return n;
		}

		tp = n;
		n = tnode_get_child_rcu(n, index);
		}

		l = leaf_new(key);
		l = leaf_new(key, new);
		if (!l)
		return NULL;
		return -ENOMEM;

		/* retrieve child from parent node */
		if (tp)
		n = tnode_get_child(tp, get_index(key, tp));
		else
		n = rcu_dereference_rtnl(t->trie);

		/* Case 2: n is a LEAF or a TNODE and the key doesn't match.
		*
		@@ -1048,7 +968,7 @@ static struct tnode fib_insert_node(struct trie t, u32 key, int plen)
		tn = tnode_new(key, __fls(key ^ n->key), 1);
		if (!tn) {
		node_free(l);
		return NULL;
		return -ENOMEM;
		}

		/* initialize routes out of node */
		@@ -1064,20 +984,47 @@ static struct tnode fib_insert_node(struct trie t, u32 key, int plen)
		}

		/* Case 3: n is NULL, and will just insert a new leaf */
		if (tp) {
		NODE_INIT_PARENT(l, tp);
		put_child(tp, get_index(key, tp), l);
		put_child_root(tp, t, key, l);
		trie_rebalance(t, tp);

		return 0;
		}

		static int fib_insert_alias(struct trie t, struct tnode tp,
		struct tnode l, struct fib_alias new,
		struct fib_alias *fa, t_key key)
		{
		if (!l)
		return fib_insert_node(t, tp, new, key);

		if (fa) {
		hlist_add_before_rcu(&new->fa_list, &fa->fa_list);
		} else {
		rcu_assign_pointer(t->trie, l);
		struct fib_alias *last;

		hlist_for_each_entry(last, &l->leaf, fa_list) {
		if (new->fa_slen < last->fa_slen)
		break;
		fa = last;
		}

		return l;
		if (fa)
		hlist_add_behind_rcu(&new->fa_list, &fa->fa_list);
		else
		hlist_add_head_rcu(&new->fa_list, &l->leaf);
		}

		/*
		* Caller must hold RTNL.
		*/
		/* if we added to the tail node then we need to update slen */
		if (l->slen < new->fa_slen) {
		l->slen = new->fa_slen;
		leaf_push_suffix(tp, l);
		}

		return 0;
		}

		/* Caller must hold RTNL. */
		int fib_table_insert(struct fib_table tb, struct fib_config cfg)
		{
		struct trie t = (struct trie )tb->tb_data;
		@@ -1205,19 +1152,13 @@ int fib_table_insert(struct fib_table tb, struct fib_config cfg)
		new_fa->fa_slen = slen;

		/* Insert new entry to the list. */
		if (!l) {
		l = fib_insert_node(t, key, plen);
		if (unlikely(!l)) {
		err = -ENOMEM;
		err = fib_insert_alias(t, tp, l, new_fa, fa, key);
		if (err)
		goto out_free_new_fa;
		}
		}

		if (!plen)
		tb->tb_num_default++;

		fib_insert_alias(l, fa, new_fa);

		rt_cache_flush(cfg->fc_nlinfo.nl_net);
		rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, tb->tb_id,
		&cfg->fc_nlinfo, 0);
		@@ -1406,9 +1347,36 @@ found:
		}
		EXPORT_SYMBOL_GPL(fib_table_lookup);

		/*
		* Caller must hold RTNL.
		static void fib_remove_alias(struct trie t, struct tnode tp,
		struct tnode l, struct fib_alias old)
		{
		/* record the location of the previous list_info entry */
		struct hlist_node **pprev = old->fa_list.pprev;
		struct fib_alias fa = hlist_entry(pprev, typeof(fa), fa_list.next);

		/* remove the fib_alias from the list */
		hlist_del_rcu(&old->fa_list);

		/* if we emptied the list this leaf will be freed and we can sort
		* out parent suffix lengths as a part of trie_rebalance
		*/
		if (hlist_empty(&l->leaf)) {
		put_child_root(tp, t, l->key, NULL);
		node_free(l);
		trie_rebalance(t, tp);
		return;
		}

		/* only access fa if it is pointing at the last valid hlist_node */
		if (*pprev)
		return;

		/* update the trie with the latest suffix length */
		l->slen = fa->fa_slen;
		leaf_pull_suffix(tp, l);
		}

		/* Caller must hold RTNL. */
		int fib_table_delete(struct fib_table tb, struct fib_config cfg)
		{
		struct trie t = (struct trie ) tb->tb_data;
		@@ -1432,7 +1400,6 @@ int fib_table_delete(struct fib_table tb, struct fib_config cfg)
		return -ESRCH;

		fa = fib_find_alias(&l->leaf, slen, tos, 0);

		if (!fa)
		return -ESRCH;

		@@ -1461,33 +1428,19 @@ int fib_table_delete(struct fib_table tb, struct fib_config cfg)
		if (!fa_to_delete)
		return -ESRCH;

		fa = fa_to_delete;
		rtmsg_fib(RTM_DELROUTE, htonl(key), fa, plen, tb->tb_id,
		rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id,
		&cfg->fc_nlinfo, 0);

		fib_remove_alias(l, fa);

		if (!plen)
		tb->tb_num_default--;

		if (hlist_empty(&l->leaf)) {
		struct tnode *tp = node_parent(l);

		if (tp) {
		put_child(tp, get_index(l->key, tp), NULL);
		trie_rebalance(t, tp);
		} else {
		RCU_INIT_POINTER(t->trie, NULL);
		}
		fib_remove_alias(t, tp, l, fa_to_delete);

		node_free(l);
		}

		if (fa->fa_state & FA_S_ACCESSED)
		if (fa_to_delete->fa_state & FA_S_ACCESSED)
		rt_cache_flush(cfg->fc_nlinfo.nl_net);

		fib_release_info(fa->fa_info);
		alias_free_mem_rcu(fa);
		fib_release_info(fa_to_delete->fa_info);
		alias_free_mem_rcu(fa_to_delete);
		return 0;
		}

		@@ -1626,7 +1579,7 @@ backtrace:
		put_child_root(pn, t, n->key, NULL);
		node_free(n);
		} else {
		leaf_pull_suffix(n);
		leaf_pull_suffix(pn, n);
		}

		/* if trie is leaf only loop is completed */

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